Comparison of feeding guild structure and ecomorphology of intertidal fish assemblages from central California and central Chile

Abstract

The hypothesis of ecological and morphological convergence of the taxonomically distinct intertidal fish assemblages from central California, USA, and central Chile was tested by comparing the feeding guild structures and the morphologies associated with food capture and processing of guild members from each region. We determined the diets of the most abundant intertidal fishes from 3 central California sites by examining gut contents. A matrix of dietary overlap among species within the Californian and Chilean assemblages (diets of Chilean fishes determined in another study) was constructed, and statistically significant guilds were determined using a bootstrapping procedure. Ten morphological features were examined for species in each region, and the relationship between diet and consumer morphology was evaluated. Three feeding guilds, omnivore, microcarnivore, and carnivore, were common to both regions, but a fourth guild, polychaete feeders, was unique to California. Feeding guild structure was not associated with phylogenetic relatedness within either assemblage. An assemblage-wide relationship between diet and morphology was found in each assemblage, but only a few associations between diet and morphology were common to both regions. In both California and Chile, omnivores tended to have longer digestive tracts and closer-set gill rakers, microcarnivores tended to have larger relative mouth heights, and all carnivorous fishes tended to have shorter guts and more widely spaced gill rakers. Overall, interregional morphological patterns were associated with phylogenetic relatedness, rather than with dietary similarities.

Ecomorphology and resource use by dominant species of tropical estuarine juvenile fishes

“…It is known that several habitat characteristics and environmental factors can influence community structure and play a role in species distribution and community organization, exceeding that played by biotic factors. Coexistence in many fish assemblages is due to morphological and spatial segregation (Boyle & Horn, 2006;Costa & Cataudella, 2007;Sampaio et al, 2013).…”

Fish functional groups in a tropical wetland of the Yucatan Peninsula, Mexico

“…The functional characterization of fish species was based on the method proposed by Villéger et al (2010) using two key functions: food acquisition and locomotion. Food acquisition considers functional traits related to the size of food items, feeding method in the water column, filtering ability, prey detection and trophic position (Kramer & Bryant, 1995;Sibbing & Nagelkerke, 2001;Karpouzi & Stergiou, 2003;Boyle & Horn, 2006;Villéger et al, 2010). Likewise, locomotion is a measure related to habitat use, vertical position in the water column, hydrodynamism, fin use for manoeuvrability, and propulsion and acceleration efficiency (Webb, 1984;Sibbing & Nagelkerke, 2001;Dumay et al, 2004;Fulton et al, 2001;Villéger et al, 2010).…”

“…Two key functions have been recognized: locomotion and food acquisition. Locomotion is related to fish swimming behaviour and habitat use, whereas food acquisition describes the trophic position and foraging behaviour in the water column (Dumay et al, 2004;Boyle & Horn, 2006;Villéger et al, 2010).…”

Tidepool fish assemblages of Gorgona Island, Colombian Pacific coast: a local and regional comparison

“…At regional scales, few attempts have been made to document tidepool fish assemblage differences, but recently Boyle & Horn (2006) made comparisons at different levels of central Chile and California tidepool fish assemblages in the Eastern Pacific finding no common species and only two shared families (Gobiesocidae and Clinidae). The present regional comparison of tidepool ichthyofaunas between the temperate and tropical regions of the Eastern Pacific Ocean shows taxonomic differences even at the family level in line with the observations of Prochazka et al (1999).…”